migrated warning system to json file

components/WarningHeader.tsx

@@ -1,27 +1,80 @@
+import { start } from "repl";
+
+import { parse } from "date-fns";
+import { utcToZonedTime, zonedTimeToUtc } from "date-fns-tz";
 import { GetStaticProps } from "next";
-import { Warning } from "pages/api/currentWarning";
 import React, { useState, useEffect } from "react";
 
 import { getCurrentTerm } from "@/lib/events";
 
+import warnings from "../content/warnings/warnings.json";
+
 import styles from "./WarningHeader.module.css";
 
-export function WarningHeader() {
-  //  We can't use getStaticProps since its a component, and we can't put it getStaticProps in its parents because nextjs doesnt support it in the _app.js
-  const [warning, setWarning] = useState<Warning | null>(null);
+// Had to add these functions here, since we cannot use import the file from ./lib/events since that uses libraries only on the serverside
+const WARNING_DATE_FORMAT = "MMMM dd yyyy HH:mm";
+function getLocalDateFromEST(date: Date) {
+  return utcToZonedTime(
+    // The parsed date is in EST
+    zonedTimeToUtc(date, "America/Toronto"),
+    Intl.DateTimeFormat().resolvedOptions().timeZone
+  );
+}
 
-  useEffect(() => {
-    fetch("/api/currentWarning/")
-      .then((res) => res.json())
-      .then((data) => {
-        setWarning(data);
-      })
-      .catch((err) => {
-        console.error(err);
-      });
+interface Warning {
+  message: string;
+  startDate: string;
+  endDate: string;
+}
+
+function getCurrentWarning(): Warning | null {
+  const today = new Date();
+  let currentWarning: Warning | null = null;
+
+  warnings.forEach((warning) => {
+    if (!warning.startDate || !warning.endDate) {
+      console.error("INVALID WARNING:", warning);
+    }
+
+    // convert dates to date objects in EST time zone
+    let startDate = parse(warning.startDate, WARNING_DATE_FORMAT, new Date());
+    let endDate = parse(warning.endDate, WARNING_DATE_FORMAT, new Date());
+
+    if (
+      !startDate ||
+      !endDate ||
+      isNaN(startDate.getTime()) || // this checks if the parsed date is not valid (eg. wrong format)
+      isNaN(endDate.getTime())
+    ) {
+      console.error("WARNING WITH INVALID DATES:", warning);
+      return; // skip to next warning in loop, this one is invalid
+    }
+    startDate = getLocalDateFromEST(startDate);
+    endDate = getLocalDateFromEST(endDate);
+
+    // check if current time is in warning range
+    if (
+      startDate.getTime() < today.getTime() &&
+      endDate.getTime() > today.getTime()
+    ) {
+      if (currentWarning) {
+        console.error(
+          "ERROR: TWO WARNINGS SCHEDULED AT SAME TIME! ",
+          currentWarning,
+          warning
+        );
+      }
+      currentWarning = warning;
+    }
   });
 
-  if (!warning || !warning.content || warning.content == "") {
+  return currentWarning;
+}
+
+export function WarningHeader() {
+  const warning = getCurrentWarning();
+
+  if (!warning || warning.message == "") {
     return (
       <div
         className={styles.warning}
@@ -30,5 +83,5 @@ export function WarningHeader() {
     );
   }
 
-  return <div className={styles.warning}>{warning.content}</div>;
+  return <div className={styles.warning}>{warning.message}</div>;
 }

content/warnings/warnings.json

@@ -0,0 +1,12 @@
+[
+	{
+		"startDate": "February 15 2022 00:00",
+		"endDate": "March 25 2022 18:00",
+		"message": "This is test warning in FEB!"
+	},
+	{
+		"startDate": "January 29 2022 21:00",
+		"endDate": "January 30 2022 18:00",
+		"message": "This is a sample warning"
+	}
+]